The invention relates to a calibration measurement device for steady-state thrust of a 4-25N attitude control engine in a thermal vacuum environment. The calibration measurement device comprises a base transfer frame, shock absorbing blocks, a fixed frame, a balance transfer plate, a single-component balance measurement device, a propellant pipeline, propellant pipeline fixing devices and an in-situ calibration device, wherein the shock absorbing blocks are uniformly mounted between the base transfer frame and the fixed frame; the propellant pipeline fixing devices are fixedly mounted on the periphery of the fixed frame; the propellant pipeline is mounted through the propellant pipeline fixing devices, one end of the propellant pipeline is communicated with an external propellant supply system, and the other end of the propellant pipeline is communicated with a propellant inlet of a to-be-measured attitude control engine; the single-component balance measurement device is mounted at one end of the fixed frame through the balance transfer plate, and the in-situ calibration device is mounted at the other end of the fixed frame. The calibration measurement device meets the requirements of the 4-25N attitude control engine for low thrust calibration measurement and solves the problems that high uncertainty is caused by pipeline constraint, high temperature and vibration in a measurement process, calibration before test run is not proper, the calibration precision is poor and the like.